In the past, a measurement apparatus (inspection apparatus) for measuring a cross-sectional shape of an outer circumference edge part of a semiconductor wafer has been proposed (see Patent Literature 1). This measurement apparatus projects light to the outer circumference edge part of a semiconductor wafer parallel to the surface of the semiconductor wafer and in its tangential direction, has the light passing the outer circumference edge part and proceeding via an optical system forming a telecentric structure received by an image sensor, and thereby forms a cross-sectional projection of the outer circumference edge part on the image sensor. Further, two-dimensional dimensions of the outer circumference edge part of the semiconductor wafer are measured from the image corresponding to the cross-sectional projection of the outer circumference edge part of the semiconductor wafer obtained based on the signal output from the image sensor.
According to such a measurement apparatus, the two-dimensional dimensions of the outer circumference edge part of the semiconductor wafer can be measured, so it is possible to inspect the suitability of the shape of the outer circumference edge part of the semiconductor wafer based on the measurement results.
In this regard, the outer circumference edge part of a semiconductor wafer is preferably inspected not only for the shape, but also for the presence of cracks, particles, or other defects at the outer circumference edge part. In the past, an inspection apparatus performing that type of inspection has been proposed (see Patent Literature 2). This inspection apparatus has a line sensor capturing an outer circumference end face of the outer circumference edge part of the semiconductor wafer, a line sensor capturing a slanted surface at an outer circumference rim of one surface of the semiconductor wafer, and a line sensor capturing a slanted surface at an outer circumference rim of the other surface of the semiconductor wafer. Further, using the shading distribution, color distribution, or other state of the outer circumference edge part of the semiconductor wafer obtained based on the signals detected from the line sensor, the presence of cracks, particles, or other defects at the outer circumference end face or slanted surfaces of the outer circumference edge part of the semiconductor wafer is judged.
According to this inspection apparatus, even the presence of defects of the outer circumference edge part of the semiconductor wafer which cannot be found by visual inspection can be precisely inspected.
Patent Literature 1: Japanese Patent Publication (A) No. 2006-145487
Patent Literature 2: Japanese Patent Publication (A) No. 2003-243465